mog75,
Trail Boss requires a lot of "bullet pull" to burn consistently, not just from a sturdy crimp but from the case itself. This is contrary to what a lot of people would guess.
Found this to be true myself. Heavy for caliber bullets and clean cases help a bunch. Normal crimp. Thrown charges, then trickle up to your desired weight seems to work better. Those big doughnut granules will play havoc sometimes on thrown charges.
